1. Field of the Invention:
The present invention relates to a color reproduction apparatus having plural color reproduction ranges and a color signal-processing method therefor, and more particularly, to a color reproduction apparatus having plural color reproduction ranges and a color signal-processing method therefor capable of displaying an inputted color signal in a selected color gamut.
2. Description of the Related Art:
Generally, a color reproduction apparatus for reproducing colors, such as a monitor, scanner, printer, or the like, uses a color space or a color model appropriate for an application field thereof. For example, color image print apparatuses use a Cyan Magenta Yellow (CMY) color space, and color Cathode Ray Tube (CRT) monitors or computer graphic apparatuses use a Red Green Blue (RGB) color space. Apparatuses for handling hue, saturation, and intensity use an Hue Saturation Intensity (HSI) color space. In addition, even a Commission Internationale d'Eclairage (CIE) color space is used for definition of so-called device-independent colors that can be accurately reproduced in any kind of apparatuses, and such a CIE color space can be typically the CIE-XYZ, CIE-LUV, or CIE_LAB color space, or the like. CIE-LUV is a CIE-based color space used to represent additive color systems, including color lights and emissive phosphor displays. CIE-LAB is an independent color space used to represent subtractive systems, where light is absorbed by colorants, for example inks and dyes.
Although the types of color reproduction apparatuses can depend on a color space being used therefor, it is conventional to use three primary colors. For example, in an RGB color space used for color monitors or computer graphic apparatuses, three primary colors of red, green, and blue are used which can be added together, and, in a CMY color space used for color image print apparatuses, three primary colors of cyan, magenta, and yellow are used.
A color reproduction range that a color reproduction apparatus can reproduce is determined by the primary colors used by the apparatus. When a color reproduction apparatus reproduces images of a general broadcasting specification or a standard color signal specification, the color reproduction apparatus represents an input image by unchangeably using the primary colors specified in the broadcasting specification or standard.
Accordingly, when the color reproduction range of an inputted color signal is narrower than the color gamut of the color reproduction apparatus reproducing the inputted color signal, all the color reproduction range implementable by the color reproduction apparatus is not used. Further, quantization errors occur in the process of mapping the color reproduction range between the inputted color signal and the color reproduction apparatus reproducing the color signal. Still further, hardware implementation is difficult, requiring a very complicate algorithm for the process of mapping the color reproduction range.
Further, in a color reproducing apparatus, an input color signal can be reproduced according to the specification of the input color signal, but it is impossible to reproduce new colors according to user's selection. For example, the SMPTE color bars (SMPTE-C) are a type of television test pattern, and is a dominant video standard by the Society of Motion Picture and Television Engineers (SMPTE). In a color reproduction apparatus, such as an Light Emitting Diode (LED) display device, when an input such as SMPTE-C is provided, the LED display device can reproduce the color signal of the SMPTE-C broadcasting specification only within the LED color reproduction range.
Accordingly, a method for a display device is required which can reproduce an input color signal of diverse standard specifications selected by users or of a specification defined by users.